If you follow the outlined procedure, but your circuit still can't POP:

- Check if it POPs with DC input. If POP does not converge with DC input, no amount of synchronization will help.
- Run a longer synchronization transient. Make sure that the DAC_sync value settles to a constant for the latter part of the transient. If ISYNC looks like it takes forever to converge, increase the loop gain.
- Make sure that the target current is set appropriately.
- Try manually adjusting the current range.
- Send an e-mail to support@simplis.com.